Which ingredient is a primary component of a Rum Runner cocktail?

The Rum Runner cocktail is fundamentally associated with rum, particularly because the drink's name itself signifies a strong connection to this spirit. Light rum serves as the primary base ingredient, contributing not only the essential rum flavor but also the smoothness and sweetness that characterize many rum-based cocktails.

The combination of various fruit juices and other flavors that typically accompany light rum in a Rum Runner further enhances the cocktail experience, but the essential backbone remains the rum itself. This is why light rum is identified as the key component of the cocktail, solidifying its role as the primary ingredient that defines the drink's identity. Other spirits like gin, tequila, and whiskey, while they can be used in a multitude of cocktails, do not play a role in the classic Rum Runner formulation, helping to clarify why they are not suitable choices in this context.